In acute wounds, modest amounts of thin, pale-yellow or straw-coloured exudate in a healing wound is considered normal. In chronic wounds, the colour, consistency, and amount of exudate may change as a result of various physiological processes (Cutting, 2004; WUWHS, 2019).

Serous Clear, amber, thin and watery Often considered normal but may be associated with infection by bacteria such as Staphylococcus aureus
Fibrinous Cloudy and thin, with strands of fibrin A response to inflammation purulent exudate containing white blood cells and bacteria
Serosanguineous Clear, pink, thin and watery Due to the presence of red blood cells
Sanguineous Reddish, thin and watery Low protein content
Seropurulent Yellow or tan, cloudy and thick Presence of infection. Liquefying of necrotic tissue
Purulent Opaque, milky, sometimes green, thick May be indicative of bacterial infection e.g. Pseudomonas aeruginosa
Haemopurulent Reddish, milky and viscous Established infection
Haemorrhagic Dark red, thick Infection, trauma. Capillaries break down easily and bleed

(Adapted from Benbow, 2007; WUWHS, 2019; Wounds UK BPS, 2013)

In normal wound healing, exudate volume will decrease as healing occurs.